The Biodiversity+ Precursors are the first set of activities that ESA initiates during the pilot phase (2020-2022) of the ESA-EC Flagship Action on Biodiversity and Vulnerable Ecosystems. They consist of 3 parallel Earth System Science studies (respectively on Terrestrial ecosystems, Freshwater ecosystems and Coastal ecosystems) which will analyse the major knowledge gaps and science questions on biodiversity and vulnerable ecosystems, assess how the recent and future Earth Observation systems can help address these scientific challenges in biodiversity knowledge, demonstrate the adequacy of Earth System Science approaches with a number of pilot demonstrations called Earth System Science Pilots for Biodiversity, and develop a Science Agenda and a scientific roadmap.